Valve for eliminating odor and smoke in exhaust gases



April 14, 19360 CRABB 2,037,459

VALVE FOR ELIMINATING ODOR AND SMOKE IN EXHAUST GASES Filed May 2, 19322 Sheets-Sheet 1 gwuantoo L. M. CRABB I April 14, 1936.

VALVE FOR ELIMINATING ODOR AND SMOKE IN EXHAUST GASES Filed May 2, 19322 Sheets-Sheet 2 3 7 a a a m a 0 fl I 2 a 8 2 I M 7 y m Patented Apr.14, :I1Q36 VALVE FOR ELIMINATING ODOR AND SMOKE IN EXHAUST GASES LesterM. Crabb, Flint, lvlich., assignor to Gen eral Motors Corporation,Detroit, Mich., a corporation .of Delaware Application May 2 1932 SerialNo. 608,649

2 Claims. (Cl. 137-153) When the throttle valve of the carburetor of aninternal combustion engine is suddenly closed, the exhaust gases becomesmoky and acquire an obnoxious odor. My experiments have shown that, toa large extent, the smoke and obnoxious odor are the result of thepresence of incompletely burned fuel in the exhaust gases.

This invention relates to a method of and apparatus for. eliminatingincompletely burned fuel and the smoke and obnoxious odor which resulttherefrom from the exhaust gases of an internal combustion engine duringperiods of rapid deceleration. i

I have found that the presence of incompletely burned fuel in theexhaust gases of an internal combustion engine during periods of rapiddeceleration is the result of the failure to supply, during suchperiods, suflicient air to the cylinders of the engine to completelyburn the fuel supplied thereto. My experiments have further shown thatthis condition can be remedied and the smokiness and obnoxious odor ofthe exhaust gases resulting therefrom can be eliminated, withoutaffecting the ratio of fuel to air in the combustible mixture suppliedtothe cylinders of the engine at any other time than during periods ofrapid deceleration, by admitting to the induction system of the engineon the engine'side of the carburetor, during periods of rapiddeoeleration only, sufficient air to insure complete combustion of allof the fuel supplied to the cylinders of the engine. The fact that,during periods during which deceleration is so rapid that there issufficient incompletely burned fuel in the. exhaust gases to causesmokiness and obnoxious odors, the pressure in the induction system ofan internal combustion engine on the engine side of the carburetor isconsiderably lower than at any other time during the opera- 0 tion ofthe engine makes it possible to employ very simple mechanism to effectthe admission of air during such periods without affecting the operationof the engine at any other time. In its simplest form, the mechanism mayconsist merely of a passage through which air may enter the intakemanifold of the engine from the atmosphere and a valve urged by thepressure of the atmosphere, from a position in which the passage isclosed to a position in which it is open, against the intake manifoldpressure and the resistance of a spring which is of such strength thatthe pressure of the atmosphere will be sufficient to open the passageonly when the intake manifold pressure reaches a value below that whichit assumes at any time other than when deceleration is so rapid thatsufficient incompletely burned fuel would occur in the exhaust gases tocause them to be smoky and have an obnoxious odor. However, since, whenthe passage is open, the pressure in the intake manifold 5 immediatelyrises, it is preferable, in order to maintain the passage opensufficiently long to admit to the intake manifold sufficient air toinsure complete combustion of all of the fuel which enters the cylindersof the engine during 10 the period under consideration, to constructand/or arrange the valve so that a smaller difference in pressure isnecessary to maintain it in the position in which the passage is openthan to move it to this position from the posi- 15 tion in which thepassage is closed.

For a better understanding of the nature and objects of the presentinvention, reference is made to the following description of thepreferred forms of 'airadmission mechanism which are illus- 20 trated inthe accompanying drawings.

In the drawings: Figure 1 shows an internal combustion engine on whoseintake manifold there is installed air admission mechanism in accordancewith my 25 invention. 1

Figure 2 is an enlarged fragmentary transverse section through theinstallation shown in Figure 1, taken on the line 2-2 of Figure 3.

Figure 3 is a section taken on the line 3-3 of 30 Figure 2, showing thevalve in closed position.

Figure a is a section taken on the line $4 of Figure 2, showing thevalve in open position,

Figure 5 is a perspective view of a second form of air admissionmechanism.

Figure 6 is a perspective view of a third form of air admissionmechanism.

Figure 7 is a section similar to Figure 3, but showing a fourth form ofairadmission mechanism.

Figure 8 is a section taken on the line t-d of Figure 7.

Figure 9 is a section similar to Figures 2 and 8, but showing a fifthform of air admission mechanism. 45

In the drawings, 1 have illustrated the mechanism for admitting air tothe induction system of an internal combustion engine on the engine sideof the carburetor during periods of rapid deceleration as applied to thepropelling engine 59 of an automotive vehicle because it is particularlyuseful in connection with such an engine since more people are subjectedto the effects of its exhaust gases than to the exhaust gases of staionary engines. On the engine, there is 55 installed a duplex"carburetor III of which each mixture passage is connected through one ofthe passage in the passages II and I2 of an'intake manifold l5 to intakeports of the engine.

The air admission mechanism which is illus-- trated in Figures 1 to 4 ofthe drawings includes a body I4 in which. there is provided acylindrical bore I 5 which extends from one end of the body to a pointadjacent the other end. The open end of the bore is closed by a head l5which carries a pin I! which projects axiallyinto the bore. Into theclosed end of the bore l5, there extends a form of a bore II which is ofsmaller diameter than and disposed coaxially with respect to the borel5. Over the outer end of the passage l8, there is disposed a dirtexeluding shield is. Within the bore l5, there I is snugly fitted toslide a piston valve on whose head end there is provided a coaxialextension 2| of reduced diameter which is adapted to fit passage l8. Acoil spring 23, of

tion in which it is shown in Figure 3 of the drawings. Through thebottom of the body l4 into the bore l5 at such points that they arecovered erably provided on the upper surface of the manifold l3 directlyabove the riser, a plane surface through which into each of the pasagesI I and 12 To install the air admission mechanism hereinbefore describedon the manifold l3, the former is seated on the plane surface with oneof the bores 24 in axial alignment with each of the bores 25 and thensecured in place by screws 21 which on the body and into the manifold.

The air admission mechanism 28 which is illustrated in Figure 5 isadapted to be installed in body and a groove course, be understood thatthe plane lustrated in Figures 'l'and 8 does to 4 and differs from to 4only. inthat bores 24 and the the piston valve is adjacent the head endare eliminated and in that the groove 35 in Figure 5 is replaced by aslot 32 which extends completely through the bottom of the body. v

The air admission in 33 which is ilnot differ essentially from thatwhich is illustrated in the precedingflguresexceptinthat thetwo bores 24extend through ears of the body surfaceon are replaced by a singlethreaded bore 34 and in I that communication between the bore 34 and thespace between the head and the piston valve 25 is established byintersecting bores 35 and 36. To facilitate installation of themechanism illustrated in Figures 7 and s, thereis provided in themanifold 31 directly above the riser, a threaded bore 35 which entersboth of the passages I I and I2. The mechanism 33 is preferablyconnected to the manifold by a hollow externally threaded fitting 38-which is screwed into the threaded bores 34 and 38.

The air admission trated, in Figure, 9 of the drawings, includes acylindrical body 4| in which there is provided a cylindrical bore 42which extends from one end thereof to a .point adjacent the other endand on which there is provided a reduced coaxial threaded extension 43through which there extends coaxially into the bore 42 a bore 44, whichis of smaller diameter than the bore 42.

Into the end of the body 4| opposite that on which the extension 43 isprovided; there is threaded an annular valve seat 45. Within the bore42, there is located a valve 46 which has a longitudinally groovedcylindrical body which is adapted to slide in the bore 42 and a taperedouter end which is adapted to seat on the walls of the opening in theseat 45. A coil spring 41 which is located within the bore 42 urges thevalve 45 to the position in which the drawings in which it functions asa closure for the opening in the seat 45.

The air admission mechanism which is illustrated in. Figure 9 is adaptedto be installed on the manifold 45 by screwing the extension 43 into athreaded opening 45 which communicates with both of the branches I I and(2 of the manifold.-

It will be noted that the valves 20 and 46 of the air admissionmechanisms illustrated in the drawings and hereinbefore described are sodisposed that they may be moved from positions in which they permit thepassage of air from the atmosphere into the passages II and I2 of theintake manifolds (through the passage l5 and the bores I5, 24, and 25 inFigures 1 to 5; through the opening l5. thebo're ii, the slot 32 and thebores 25 in Figure 6; through the opening l5 and the bores I5, 34 and 35in Figures 7 and 8; and through the opening in the seat 45, the groovesin the valve 45 and the bores 42, 44, and 48 in Figure 9) to positionsin which they prevent the passage of air from the atmosphere into thepassages II and I2. It will be further observed that the springs'23 and41 urge the valves 25 and 45 to the latterpositions and that since thepressure of the atmosphere is applied to the outer ends of the valvesand the pressure within the passages H and I2 to the inner ends of thevalves (through bores 25 and 24 and the groove tends to moveffiievalvesto the former pomtions.

which lation is so rafild that suilicient in- As hereinbefordhhentioned,the pressure within the 'andl2dui-ing peiiodsduring completely burnedfuel 'wouldoccur in the exhaust gases to cause them to be men and havean obnoxious odor is considerably lem than at mechanism which isillusbores 43. 44, and 42 inFigure 9) ,ressurewithinthepassages H and I2difference between the pressure of the atmosvphere on the portions ofthe valves on which it.

is exerted when the valves are in positions in which the passages whichconnect passages II and I2 to the atmosphere are closed. arid thepressure within the passages II and I2 will move the valves to suchpositions that they will permit the entrance of air into the passagesonly when the difference between the pressure of the atmosphere and thpressure within the passages exceeds that whi h obtains under any otherconditions oi pptration of the engine. It will, of

course, beobvious that the admission 01' air will.

begin only when the difference between the pressure of the atmosphereand the pressure within the passages H and I2 exceeds this predeterminedvalue, but that since, when the valves reach positions in which thepassages which connect'the passages II and I! with the atmosphere areopen, the areas of their end surfaces on which the pressure of theatmosphere is exerted are greater than those on which the pressure ofthe atmosphere is exerted when the passages are closed, the valves willremain in the pressure of the atmosphere is exerted when the passagesare open and-when the passages are closed, the volume of air admitted tothe passages and between the time the valves reach positions in whichthe passages are openand the time the valves return to positions inwhich t the passages are closed is determined by the dif- 'cientlylarger than the areas of the end surfaces on which the pressure of theatmosphere is ex-- ference between the areas of the end surfaces 01' thevalves on which the pressure of the atmosphere is exerted when thepassages are open and when the passages are closed. Consequently, whileif the areas of the end surfaces of the valves on which the pressure oithe atmosphere is exerted when the passages are open are made sum:-

erted when the, passages are closed, the as will remainopen suillcientlylong to admit to the passages II and I2 suificlent air to insurecomplete combustion of all fuel which enters the engine cylinders and toeliminate smoke and odors in the exhaust during periods of rapiddeceleration, air will not be admitted to the passages ll and I2 throughthe passages which connect them with the atmosphere at other times thanduring periods of rapid deceleration ii the springs 23 and 41 are madeofsuch strength that the difterence between the pressure 01' theatmosphere on the portions of the valves on which it is exerted when thevalves are in positions in which the passages which connect the passagesII and I2 to the atmosphere are closed and the pressure within thepassages II and I 2 will become suflicient to move the valves topositions in which the passages are open only during periods of rapiddeceleration.

I claim: 1. In mechanism for regulating admission of to cylinders 01'an'internal combustion engine, a valve housing in which there isprovided a bore which is closed to the atmosphere at one end, a smallerbore extending into the other end of the first mentioned bore andcommunicating with the atmosphere, a valve which fits and is-slidable inthe first mentioned bore and on which there is provided an extensionwhich fits and is slidable in the second mentioned bore, a spring urgingthe valve to a position in which the extension is located in the secondmentioned bore, a passage adapted to be connected with the firstmentioned passage and extending into the first mentioned bore at such apoint that it is closed to .the atmosphere by the valve when the valveis in the position tovwhich it is urged by the spring, and a passagewhich communicates with the second mentioned passage and the end of thefirst mentioned bore which is closed to the atmosphere 2. 'In mechanismfor regulating admission of air into the passage connecting thecarburetor to,

cylinders of an internal combustion engine, a valve housing inwhichthere is provided a bore which is closed to the atmosphere at oneend, a

smaller bore extending into the other end of the first mentioned boreand communicating with tioned bore at such a point that it communicateswith the atmosphere through the mentioned bores when the extension iswithdrawn from the second mentioned bore and is closed to theatmospher'e when the valve is in the position towhichitisurgedbythespring.

p LESTER M. CRABB.

15 air into the passage connecting the carburetor

